At present, in a process of casting and machining of a low-pressure aluminum alloy wheel, a gate on a casting blank must be removed before machining due to a casting filling process; otherwise, subsequent machining operation will be affected. According to a traditional degating practice, the gate is cut by a specific drilling machine after the following operation: a blank is cast and quenched, X-ray flaw detection is performed on the wheel to confirm that no defect exists and the wheel blank is placed on a degating drilling machine and positioned by an operator. This method increases labor intensity for the operator as the operator needs to place wheels continuously and remove the wheels after processing, is not conducive to mechanical automation production, and greatly reduces machining production efficiency. In the meantime, during cutting, since positioning is carried out at the lower end of a rim of a hub and a cutting position is at a flange in the center of the upper end, it is liable to cause deformation of a spoke and difficulty in subsequent machining as well as scrap of castings of the wheels.